10 BHN shattering upon impact

[BigSlick]

Hi guys,

Sent a few 10 BHN 115's down range yesterday out of the 32 H&R.

I do my best to collect my bullets from the backstop (? steel plate at an angle) when I can.

When I went to see if I could retrieve any, all but a couple were shattered into small splinters and chips of lead.

These run about 1300 fps +/-

I shot a few last week (12 BHN) and they shattered, so I softened up the mix.

Mix is ? and ? clips ons to stick ons with a very small amount of tin.

BHN measured on a Cabin Tree.

I see lots of cast boolits on the ground at the base of the backstop so I don't think the backstop is the problem.

I pick up 9mm 115gr cast there all the time when I shoot them at about 1200 fps.

Any ideas how to keep them from shattering without going to pure ?
________
Uhwh (http://uhwh.com/)

[Char-Gar]

Reduce the antimony content of your alloy.

[44man]

I have a steel plate at an angle and I can't save a single boolit, even a 30 to 1 mix. It takes a very sharp angle, mine is only 45 degrees or so and all I get are those tiny pieces. I might get enough to make one boolit if I throw the dirt in the pot.

[FISH4BUGS]

Try casting at a lower temp. I sometimes get sprues that crack if I am casting too hot. Please feel free to correct me if I am way off base here.

[AZ-Stew]

Even a pure lead muzzle loader bullet will splatter when fired against steel. Reduce velocity or find a softer catch medium.

Regards,

Stew

[EMC45]

Just my 2 cents: I'd stop adding the tin. The WW metal is a good alloy. And with the stick ons it should be a good blend of both. On another note I once had 200gr SWC .45 ACP bullets from Miester that would crack up if they hit something hard. They were rock hard! I put one in my SAECO and it came out hard as pure Lino! Wow! They shoot good though. My bullets of pure WWM shoot great as is. No tempering, water quenching or alloying.

[montana_charlie]

I read an article ( probably on http://www.lasc.us/CastBulletNotes.htm ) where it said that bullet brittleness could be caused by too little tin in a lead/tin/antimony alloy. I seem to recall that the tin needed to equal at least half the percentage of antimony to prevent that condition.

But, in this case, I agree that striking steel will cause bullets to 'splatter', and that is probably what you are seeing. Those you find intact were probably moving pretty slow when they reached the backstop...or hit the ground first.
CM

[cohutt]

50/50 WW/PURE 200 g swc @ 800 fps vs steel RR plate gives me the quarter shaped remnants in the lower part of the pic. No tin added. I've not weighed but I figure the carcasses are 100g or so.

Is this what you are calling shattered w/ 1/2 the bullet gone or are you recovering even less? These were water dropped for convenience but sized hard afterwards to .451

http://i107.photobucket.com/albums/m284/cohutt/leadaugust2007005.jpg


(BigSlick already knows the hardcast bullet is an unfired commercial 44 240 of the type that bounced back and hit me in the face Saturday off a plate at 25-30 yards. ..... wasn't what i thought i was shooting, a real lesson for me. And yes, it did leave a mark)

[SharpsShooter]

90% of the time when shooting my 45 colt with 20:1 260gr boolits at the 100yd swinger, I see the boolit do a complete splatter. No hope of recovering anything much off of steel.

http://i146.photobucket.com/albums/r255/SharpsShooter_photos/Copy3of100B2992.jpg


SS

[BigSlick]

Thanks for the feedback guys.

Air cooled 50/50 or so plus maybe ?% tin

I walk the backstop and see all kinds of cast boolits laying around (pick em up too).

The shattering isn't a partial loss of weight. it shatters like a broken glass with little if anything even close to a piece of bullet left.

I don't know how exactly to assess the antimony content other than a seat of the pants guess based loosely off BHN.

I've shot the same alloy out of the 500 with a 460GC and got the same results, but figured it was because I sent them down range at just shy of 1700 fps with a huge meplat. As an aside, the GC looks like a copper quarter when you can find it. :mrgreen:

The 32's are almost identical to a 32-098-SWC, but in 115gr.

I would really like to retain some of the alloy without resorting to tweezers and knee pads.

Some commercial cat I've fired retains almost if not all it's weight when hitting the same backstop.

I'm kinda stumped here, I gotta save some of that alloy or it's gonna start buggin me.
________
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[grumpy one]

It sounds as if people are talking about two different subjects here: brittle fracture versus simple melting on impact due to kinetic energy being transformed into thermal energy. There are metallurgical tests that should show which is happening, starting with hitting some bullets really hard with a hammer. The 45 that hit the steel ram in the picture above obviously melted - that was not a brittle failure.

Brittle failure can be dealt with by changes in alloy or heat treatment, but melting cannot (unless you want to delete the lead). So, I suggest trying to induce brittle failure on the bench. If you can't, you may be mistaking melting for brittle fracture. If you can, you can develop an alloy that is less prone to the problem. Bench testing is more practical than range testing.

[cohutt]

When not shooting steel, I find there same bullets almost 100% with maybe a side smeared and distorted a little bit. Like hitting dirt/wood/mud after passing through paper or cardboard.

I'm assuming the backstop is a dirt berm - those full bullets are prolly just making a soft landing relatively speaking in the dirt, don't you think?

[BigSlick]

It sounds as if people are talking about two different subjects here: brittle fracture versus simple melting on impact due to kinetic energy being transformed into thermal energy. There are metallurgical tests that should show which is happening, starting with hitting some bullets really hard with a hammer. The 45 that hit the steel ram in the picture above obviously melted - that was not a brittle failure.

Brittle failure can be dealt with by changes in alloy or heat treatment, but melting cannot (unless you want to delete the lead). So, I suggest trying to induce brittle failure on the bench. If you can't, you may be mistaking melting for brittle fracture. If you can, you can develop an alloy that is less prone to the problem. Bench testing is more practical than range testing.

OK, I hammered a few pretty hard. They shattered like an ice cube. I can heat treat these if I need to but the caliber only runs 21k psi max.

As far as changing the alloy, and trying to stay under 14 or so BHN I'm all ears.
________
VAN NUYS ASSEMBLY (http://www.chevy-wiki.com/wiki/Van_Nuys_Assembly)

[grumpy one]

If you shattered them with a single stroke of the hammer, it sounds as if they are brittle. If you hammered them repeatedly and they first spread, then finally split, that's a different thing.

AFAIK you won't cure brittleness by heat treatment. It can be caused by too much antimony or arsenic, or an unsuitable ratio of antimony to tin. I don't have any decent data on that though you can probably find some by searching the internet. If you are using a mixture of pure lead and pure WW (no added magnum shot, for example) I'd suggest you try bringing the tin content up to at least half the antimony content and try the bench test again. If you have any magnum shot in the mix, try leaving it out. Some shot has high arsenic.

[leftiye]

Both copper and tin will increase toughness in a boolit. If your boolits shattered with one good blow, then maybe you could add some 95%tin/ 5% copper lead free solder to the Alloy. If 2% tin doesn't work, then you have to decide if the solder isn't costing more than the lost lead would be worth to salvage.

[MikeP]

I regularly shoot .22 long rifles into a steel bullet trap made for those rounds. The back of the trap is angled steel.

The only thing left at the bottom of the trap is lead powder. I've never seen anything that looked like a bullet.

I hold my breath when dumping the residue, because it would be too easy to breathe it in.

[ANeat]

Slick I think a couple of guys touched on this. I believe what you may be getting is more of a splash than a shatter of the bullet. Think splash like a drop of water hitting something.
A friend of mine has a indoor setup with a metal bullet trap. Even with swaged bullets it catches everything and mostly in tact, although quite a bit flatter. The 45 bullets look about like a quarter or a half dollar. The only thing is his trap has a pretty steep angle and deflects the bullet more than just stopping it.

That pic Sharpshooter posted is a real good illustration of a "splash" on the ram